A facile synthesis of 4-acylamino-tetrahydroindazoles via the Ritter reaction

A new route toward 4-acylamino- and 4-amino-substituted tetrahydroindazoles is disclosed. The title compounds are obtained in good to excellent yields in the Ritter reaction between 4-hydroxy-tetrahydroindazoles and various nitriles. The reactivity of the tetrahydroindazole-derived carbenium ion is both sufficiently high to react with trichloroacetonitrile and sufficiently selective to resist the azide functionality within its structure. The present approach adds a method to the toolbox of tetrahydroindazole chemistry and facilitates the structural modifications of the scaffold, which has found important applications in medicinal chemistry.     

A New Method of Preparing Copper Oxide from Dinitrourea Copper Salt

A new approach for the preparation of copper nanooxide by solvothermal decomposition of N, N′‐dinitrourea copper(II) salt in an aprotic solvent was developed. The resulting particles were studied by transmission electron microscopy, X‐ray photoelectron spectroscopy, and small‐angle X‐ray scattering. The effects of different solvents on shapes of the agglomerates formed are shown.     

5‐Amido‐ and 5‐Amino‐Substituted Epoxyisoindolo[2,1‐a]tetrahydroquinolines and 10‐Carboxylic Acids: Their Synthesis and Reactivity

The interactions between 4‐R‐substituted 2‐furyl‐1,2,3,4‐tetrahydroquinolines (synthesized by the Povarov reaction) and a number of alkenes have been investigated. Maleic, dibromomaleic, dichloromaleic, and citraconic anhydrides, as well as acryloyl, methacryloyl, crotonyl, and cynnamoyl chlorides were used as alkene components. It was shown that the initial N‐acylation of the tetrahydroquinolines was followed by a spontaneous [4+2]‐cycloaddition of an N‐acryloyl substituent to the furan ring. It was established that the intramolecular Diels–Alder reaction of furans is reversible, occurs stereoselectively as exo‐addition, and led to target epoxyisoindolo[2,1‐a]tetrahydroquinolines with moderate yields. Oxidation and aromatization of the synthesized products were carried out.     

Partial-state formalism and the object-subject split in quantum mechanics

A suitable general statistical framework is established by taking quantum mechanics as full, and other (state-distinguishing) statistical theories as partial theories with respect to a given relevant subset of observables. The partial theory exists and is unique up to equivalence. The choice of the simplest or canonical one is determined. The recently introduced hybrid, i.e., half quantum mechanical and half classical discrete, statistical states obtain thus their rightful place in a hierarchy of relevant quantum statistical theories. On the other hand, these states are shown to represent a derivation of the quantum object-subject split with a well-defined subject that encompasses preparator or measuring instrument in a natural way.     

Estimation of physical properties of transition metals based on a configuration model of solids

A new empirical formula for estimation of the entropyS°₂₉₈ of transition metals is suggested. On the basis of this formula some equations that enable calculation of other physical properties, for example density and molar heat capacity, have been derived.Dedicated to Prof. Dr.Kurt L. Komarek on the occasion of his 60th birthday.     

Electrospray ionization mass spectra of pentoses,hexoses, and 2-deoxy-2-fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose

Electrospray ionization (ESI) mass spectra of hexoses, pentoses, and 2-deoxy-2-fluoro-d-glucose (FDG) were investigated and compared using liquid chromatography/mass spectroscopy (LC/MS). ¹⁸F-FDG is one of the most widely used radiopharmaceuticals. This work is aimed at the possible interpretations of ESI mass spectra and at the comparison of various pentoses (arabinose, ribose, xylose), and hexoses (glucose, fructose, galactose, mannose) which can be formed during the ¹⁸F-FDG’s synthesis or decomposition. As a result, nine major associates were found in the positive and four in the negative mass spectra of all examined saccharides of which intensities and mass can be used with their retention times to determine the saccharide. M · NH₄⁺ and M · COOH⁻ were identified as the most stable associates.     

Water as a clustering agent in photolysis and photonucleation of benzaldehyde vapor

The role of water vapor in benzaldehyde photolysis and photonucleation is investigated experimentally as well as with the help of semiempirical estimation of reaction intermediates. It is shown that water molecules act as a clustering agent that brings together two benzaldehyde molecules. This mechanism may explain the experimental observation of glyoxal formation during photolysis in humid carrier gas even in the presence of oxygen, the dependence of the concentrations of glyoxal and diphenyl on water-vapor concentration, and some other unusual facts concerning minor products detected in the experiment.